A campaign worker distributes fliers in Loveland, Colo., before the November elections for the conservative group Americans for Prosperity. U.S. laws permit many nonprofit groups, both liberal and conservative, to supply unlimited funds for political advertising from donors who do not have to be identified. (Getty Images/The Denver Post/R. J. Sangosti)

Debate over the role of nonprofits in electoral politics intensified recently when the IRS scrutinized tax-exempt groups and their political activity. The IRS action followed Federal Election Commission (FEC) rulings on campaign expenditures and court decisions such as the Supreme Court's landmark 2010 ruling in Citizens United vs. FEC. That ruling permitted unlimited spending on partisan political advertising by corporations, labor unions and individuals. The government has long exempted charities, churches, social welfare groups and other nonprofit organizations from income taxes, while restricting them from engaging in partisan political activity. Watchdog groups say reforms are needed to keep nonprofits, especially those that do not have to disclose the names of donors, from exerting undue influence in elections. But some nonprofits say such regulation would trample free speech rights.